By Gabriela Baczynska and Sabine Siebold BRUSSELS (Reuters) -The European Union is planning a third package of sanctions against Moscow, EU officials said on Friday, as Ukraine’s president pleaded with the bloc for faster and more forceful steps to punish Russia for its invasion of his country. Envoys of the EU’s 27 member states agreed to freeze any European assets of Russian President Vladimir Putin and Foreign Minister Sergey Lavrov, adding to a slew of sanctions backed by the leaders at an emergency summit on Thursday night. “We are moving as quickly as we can,” said one EU official, expla…